The invention relates to a combustion engine of the Junkers type, i.e. with opposed pistons, in which the motion between piston and driveshaft and vice versa is transferred with a cam disc on the driveshaft. The engine has several cylinders, each with inlet and exhaust ports. The pistons of the engine have a cam roller to transfer the motion between the piston and the drive shaft and vice versa, the cam roller being arranged to be in contact with a cam curve on the driveshaft. The engine according to the invention has been designated the Diesex 4 engine.
Over the past three-quarters of the century our engine designers have steadily increased the number of horsepower per 100 kg weight of engines, reduced their fuel consumption per horsepower-hour and increased their combustion pressure.
At the beginning of the twentieth century, an engine of only a few horesepower would weigh 100 kg, the fuel consumption was about half a kilo or more per horsepower per hour, and the combustion pressure was about 20-30 kg/cm.sup.2. By the 1950s, these figures had been improved to 10-15 hp per 100 kg for heavy duty engines, and for aviation purposes the figures were down around 1 kg per hp, while the fuel consumption was around 1/4 kg per hp-hour for conventional engines and 0.16-0.20 kg per hp-hour for diesels. Combustion pressures had, by the 1950s, been raised to around 100 kg per cm.sup.2 for diesels, and the stresses on connecting rods and bearings began to be high. During the 1980s, the figures have been further improved by increasing the combustion pressure, which has reached 200 kg per cm.sup.2, i.e. 200 bar, but as a result connecting rods and bearings, piston bolts and crankshafts are approaching their maximum loadings, so that a change somewhere in the engine system is called for.